The present invention relates generally to phased array antennas more specifically the invention pertains to a procedure and apparatus that can correct for failures in a phased array that is controlled by a digital beamformer.
Present day array antennas provide some degree of monitoring to determine the state of operation of individual elements of the array, Failed or failing devices are replaced during the system off-time or during scheduled maintenance periods. Recently there has been an increased interest in developing methods to improve the patterns of arrays in the presence of failed or partially failed elements by re-optimising the weights applied to the remaining array elements to compensate for the failures.
The task of correcting the output of phased array antennas with failed antenna elements is alleviated, to some extent, by the systems disclosed in the following U.S. Patents, the disclosures of which are incorporated herein by reference:
U.S. Pat. No. 4,453,164 issued to Patton;
U.S. Pat. No. 4,559,605 issued to Norsworthy; and
U.S. Pat. No. 4,972,314 issued to Getzinger et al.
The above-cited references all disclose signal processing systems that process the electromagnetic signals received by phased array antennas. Unfortunately, a need remains to enhance the signals received by antennas which have missing or failed antenna elements. The present invention is intended to satisfy that need.